Syringe for hypodermic needles or the like



Anm?? 4 l NVENTOR.

W. WOLF sept. 27, 1927.

SYRVINGE FOR HYPODERMIC NEEDLES OR THE LIKE Filed Ngv. 15, 19@

Patente-d Sept. 27, 1927.

unirse sursis PATENT oFFicE.

WILLIAM WOLF, or NEW YORKN. Y.

'sYRING'EroR I- IYPoiiERivIIG NEEDLES 'ORTII'E LIKE.

Application Afleditovember 15, 1926. Serial No. 148,319.

This Vinvention relates to syringes, particu` larly such as are used With hypodermic needles. rThe air present between the :plunger andthe fluid to be injected forni air bubbles the injection of which into the tissuesy or veins of theipatient must'be avoided. W'ith the hitherto used syringes of this kind the operator accomplishes this before passing the needle which is removably attached to the syringe into the tissues of the body by first inverting the 'syringe tto bring the Vair bubble to the lvbottom of the barrel i. e. iin front of thai-luid and' then by :sloiv'lymoving the 'plunger 'upwardlytherebyexpelling the` air. This manipulation consumes vtime and entails Waste of often very valuable fluid, for some of said fluid must be expelled to completely discharge the air. This Waste may become Yconsiderable Aivhen the plunger is advancedtoo rapidly or with a jerky motion. Syringes used With liypode'rinic needles are comparatively small and delicate,

generally made of glass and the problem of discharging the air from these instruments is diiferent 'from `that of syringes of coinpaiatively large dimensions used forother purposes and 'Where rvalves or cocks' can be readily applied.

One of ythe niain objects-of this invention is to provide ineansnivhich will lsave '"uid and time by permitting the discharge of the air during `the injection and dispense With the.V necessity of previously yinverting the syringe. Y 1

Ainotherlobje'ct is to 'u'seithesiinplest possible means ffortha-t Apurpose `vso that 'the cost of manufacture of 'the' syringe will fnot 'be higher than that of ordinarysyringes 'and which willlbeeffectiveiand can be :easily 'controlled bythe operator. v

Another' object of myjinve'ntion is to lpro'- vide means whereby the syringe filledvvith the: substance used for treatment vfbeL carf ried in ones satchel to be ready vfor use Vand Vwhereby the operator is enabled-to uselonlyV part 'of the `luidfleaving the restin the plunger for later usel I i still 'further object'of thisinvention lis to provide means lwhich Will facilitate the expulsion of the fluid which during 'the eX- pulsion :of the air or during the injection may -haveeiitered the plunger.

lith these and other fobj e'cts Tin viefiv, 'fm'y invention consists y in the combination, con'- `out from the nozzle or 'theneedla I vgeven -ivhenfinovin'g 'the plunger carefully struction, and arrangement of parts as will be hereinafter more fully described anddelined in the appended claims.

In the accompanying drawing, in which similar reference characters denote corresponding parts, Fig. l is a longitudinal section of the syringe constructed according to my invention and Figs. 241 are sectional vvieivs of modifications of 'details of 'said syringe.

`As ivth the lknovvn construction, my syringe y'comprises *a barrel "10, `havinga 'nozzle 102 fand a hollow plunger l1, 'slidably vfitted therein a'nd'ivhich at its V'outerend is formed with a fin'geiipiece'or grasp 11a. 12 denotes and sloi'v'ly there will lbe a ivaste of fluid.

If'theplunger isni'ove'd too rapidly or with a jerky motion a considerably greater quanen'tails 'Waste 'of 'often very valuable Huid,

ytigtyof the fluid may be Wasted.l Suchma- -nipulation is therefore 'objectionable 'as it riccordi'ng to inyinveiitionthis objection is obviate'd by providing'the plunger with two openings 1lb,*l=l, at its opposite ends. During the injection'the outer opening lll is held closed by the linger -of the operator until th'e plungercoines close to the bottom of theba'rrel. The operator fthen' opens the air j iassage'llb as "a result of which, When the plunger ispushed further inwardly, the air instead of being forced through the nozzle into the needle, ivill pass-into the -liolloi'v y plungerfll. `=Of vcourse the air'may be forced into'the plunger before the operation and before att-aching'the needle to the nozzle, by

" closing 'the latter f and advancing thepluiiger.

ln 'Fig'. lthe openings 11b, lll", are shown in :the center of the ends of the plunger.

As the Asyringe during the operation is yheld in a more or less inclined position, the air bubble located between the inner end of the plunger and the fluid rising to the top will be displaced relative to the center of the plunger so that the passage of the air into the plunger will be obstructed by the fluid. To remedy this, the bottom or inner end of the plunger may have a number of perforations 11d as shown in the modication Fig. 1, so that no matter what the position of the syringe may be, when in use the air willreadily find an opening through which it can pass into the plunger.

As the operator cannot tell with certainty at which instant to open the outer air passage of the plunger to expel the air, it may happen that the air passage is opened before all fluid was injected into the body of the patient. Thus with the expulsion of the air into the plunger some fluid too may pass into the latter. cording to Figs. 1 and 1a the quantity of fluid allowed to pass into the plunger will be at least such as to form a film of the entire width of the plunger. To reduce this quantity to a. minimum the inner air passage leadinginto the plunger may be provided with a short projection or nozzle 13. Correspondingly the bottom of the barrel 10 or the inner end of the nozzle 10l thereof must be provided with a depression or groove 10b of such size as topermit the projection 13 to enter said groove when the plunger is moved to the extreme inner end position (Fig. 2). It will be seen that with this construction the operator can reduce the quantity of fluid that may accidentally pass into the plunger by advancing the latter while holding the outer ain passage 11 of the plunger closed, until all air is expelled from the barrel and iuid just enters the projection 13 of ther plunger. He then closes the outer air passage and advances the plungerto complete the injection.

To facilitate the closing of the outer air passage by the finger this air passage may be formed in a protuberance 11e as shown in Fig. 3 which the operator while performing the injection and without looking at the end of the plunger can quickly locate by his finger. This modication is shown in Fig. 3.

Instead of closing the outer air passage of the plunger by the finger, a cap 14 oi' 15 of glass, rubber or other suitable material may be used to lit over the protuberance 11e as in Fig. 4 or over the finger piece 11a as in Fig. 5. A cap 16 may be used also for the nozzle 10a to close the barrel (F ig. 6) to allow the syringe iilled with the fluid of being carried in ones satchel ready for use. In such case the fluid is forced into the plunger of the syringev from the nozzle of the barrel by holding the vouter air passage open. Then the latter and the nozzle of the barrel are closed by the Stoppers or caps.

With the construction ac- The expulsion of the fluid that may have entered the plunger or the nozzle thereof may be easily effected by using an auxiliary syringe 17 which may be an integral part of the main plunger as in Fig. 7 or be perinaiiently or removably attached to the same as shown in Fig. 7a. Instead a rubber ball 18 which may be mounted over the plunger may be used, as shown in Fig. 8.

Instead of a` removable cap such as shown in Figs. 4 and 5 I may use a valve. In Fig.

9 the valve 19 consists of two superposed disks pivotally connected together and having perfor-ations 191,192,which on the turning of one of the disks will be brought into alignment with one another and with the outer air passage of the plunger'.

In Fig. 10 the valve comprises a casing 2O adapted to be fixed to either permanently or removably or made integral with the outer end of the plunger. with an air passage 20, a conical seat 20b and is provided with a cone valve body 21. This-valve acting like a back stroke valve will be thrown against its seat 2Gb when the plunger is advanced and then automatically close the air passages of the casing. Suitable meaiis may be provided to unseat the valve during the advance of the plunger.

Instead of cap 15 shown in F ig. V5 a cap 15i1 may be used shown in Fig. 11. 'This cap is adapted to engage around the linger piece of the plunger and the flange l()1 of the barrel 10 when the plunger is in its innerinost position, and thus serve not only to close the air passage of the plunger but also lock the plungerfin the barrel against accidental displacement. This cap is particularly useful when the. filled syringe isl carried in the satchel. l

It is of course clear that various other modifications may be made in the construction of the syringe without departing from the principle of my invention. I therefore do not wish to limit myself to any of the details described and shown. i

What I rclaim-is:

v1. In a syringe for hypodermic needles or Thisrcasing is formed VlOl) nozzle and of such small diameter as to be capable of being controlled during operation by the linger of the operators hand.

2. In a syringe for hypodermic needles or the like a barrel and a plunger therein having air passages at the opposite ends, the air passage at the outer end being formed in an outwardly extending projection and of such small diameter as to be capable of being controlled during operation by the linger of the operators hand, for the purpose specified.

3. In a syringe for hypodermic needles or .the like, a barrel and a plunger therein 'formed with air passages at its opposite ends, the outer air passage beingformed in an outwardly extending projection and of such small diameter as to be capable of being controlled during operation by a finger of the operators hand, and means for closing said outer passage when' the syringe is not in use.

In a syringe for hypodermic needles or the like a barrel, la plunger therein formed with air passages at its opposite ends, the outer air passage of said plunger being formed in an outwardly extending projection and of such small diameter as to be controllable during operation bya linger of the operators hand, and a cap removably mounted on said projection for closing said outer air passage when the syringe is not in use. Y

5. In a syringe for hypodermic needles or the like a barrel having a nozzle to which said hypodermio needle is adapted to be attached, a removable closure for said nozzle when the syringe is not in use, a plunger having air passages at' its opposite ends, the

outer air passage of said plunger being formed in an outwardly extending projection and of such small diameter as to be controllable during operation by a finger of the operators hand, and a removable means for closing the outer air passage of said plunger when said syringe is not in use.

6. A syringe of the character described having a plunger formed with air passages extending therethrough, the outer airpassage j being made in an outwardly projecting nozzle and of such small diameter as to be controllable during operation by a linger of the operators hand.

7 In a syringe of the character described a plunger having an air passage in its outer end of such small diameter as to be controllable during operation by a linger of theoperators hand, and a plurality of air passages at its inner endfor the purpose described.

8. In a syringe of Vthe character described the combination with the barrel and plunger, of a cap removably fitted over the outer end vof said plunger and engaging said barrel to WILLIAM VOLF. 

